Search Publications

New Parallaxes of Galactic Cepheids from Spatially Scanning the Hubble Space Telescope: Implications for the Hubble Constant
DOI: 10.3847/1538-4357/aaadb7 Bibcode: 2018ApJ...855..136R

Casertano, Stefano; Anderson, Jay; Filippenko, Alexei V. +8 more

We present new measurements of the parallax of seven long-period (≥10 days) Milky Way (MW) Cepheid variables (SS CMa, XY Car, VY Car, VX Per, WZ Sgr, X Pup, and S Vul) using one-dimensional astrometric measurements from spatial scanning of Wide-Field Camera 3 on the Hubble Space Telescope (HST). The observations were obtained at ∼6 month intervals…

2018 The Astrophysical Journal
Gaia INTEGRAL eHST 449
Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming Region
DOI: 10.3847/1538-4357/aae8e1 Bibcode: 2018ApJ...869...17L

Pascucci, Ilaria; Edwards, Suzan; Banzatti, Andrea +23 more

Rings are the most frequently revealed substructure in Atacama Large Millimeter/submillimeter Array (ALMA) dust observations of protoplanetary disks, but their origin is still hotly debated. In this paper, we identify dust substructures in 12 disks and measure their properties to investigate how they form. This subsample of disks is selected from …

2018 The Astrophysical Journal
Gaia 447
The Disk Substructures at High Angular Resolution Project (DSHARP). II. Characteristics of Annular Substructures
DOI: 10.3847/2041-8213/aaf740 Bibcode: 2018ApJ...869L..42H

Hughes, A. Meredith; Wilner, David J.; Andrews, Sean M. +14 more

The Disk Substructures at High Angular Resolution Project (DSHARP) used ALMA to map the 1.25 mm continuum of protoplanetary disks at a spatial resolution of ∼5 au. We present a systematic analysis of annular substructures in the 18 single-disk systems targeted in this survey. No dominant architecture emerges from this sample; instead, remarkably d…

2018 The Astrophysical Journal
Gaia 430
The Dearth of z ∼ 10 Galaxies in All HST Legacy Fields—The Rapid Evolution of the Galaxy Population in the First 500 Myr
DOI: 10.3847/1538-4357/aab03f Bibcode: 2018ApJ...855..105O

Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D. +2 more

We present an analysis of all prime HST legacy fields spanning >800 arcmin2 in the search for z ∼ 10 galaxy candidates and the study of their UV luminosity function (LF). In particular, we present new z ∼ 10 candidates selected from the full Hubble Frontier Field (HFF) data set. Despite the addition of these new fields, we find a low…

2018 The Astrophysical Journal
eHST 369
ALMA Survey of Lupus Protoplanetary Disks. II. Gas Disk Radii
DOI: 10.3847/1538-4357/aab890 Bibcode: 2018ApJ...859...21A

Guidi, G.; Testi, L.; Hogerheijde, M. +10 more

We present Atacama Large Millimeter/Sub-Millimeter Array (ALMA) Band 6 observations of a complete sample of protoplanetary disks in the young (∼1-3 Myr) Lupus star-forming region, covering the 1.33 mm continuum and the 12CO, 13CO, and C18O J = 2-1 lines. The spatial resolution is ∼0.″25 with a medium 3σ continuum s…

2018 The Astrophysical Journal
eHST 342
The Binary Neutron Star Event LIGO/Virgo GW170817 160 Days after Merger: Synchrotron Emission across the Electromagnetic Spectrum
DOI: 10.3847/2041-8213/aab2ad Bibcode: 2018ApJ...856L..18M

Berger, E.; Chornock, R.; Fong, W. +17 more

We report deep Chandra X-ray Observatory (CXO), Hubble Space Telescope (HST), and Karl J. Jansky Very Large Array (VLA) observations of the binary neutron star event GW170817 at t < 160 days after merger. These observations show that GW170817 has been steadily brightening with time and might have now reached its peak, and constrain the emission…

2018 The Astrophysical Journal
eHST 334
Disks around T Tauri Stars with SPHERE (DARTTS-S). I. SPHERE/IRDIS Polarimetric Imaging of Eight Prominent T Tauri Disks
DOI: 10.3847/1538-4357/aab846 Bibcode: 2018ApJ...863...44A

Benisty, Myriam; Garufi, Antonio; Pinte, Christophe +7 more

We present the first part of our Disks ARound T Tauri Stars with SPHERE (DARTTS-S) survey: observations of eight T Tauri stars that were selected based on their strong (sub)millimeter excesses using SPHERE/IRDIS polarimetric differential imaging in the J and H bands. All observations successfully detect the disks, which appear vastly different in …

2018 The Astrophysical Journal
Gaia 300
In Disguise or Out of Reach: First Clues about In Situ and Accreted Stars in the Stellar Halo of the Milky Way from Gaia DR2
DOI: 10.3847/1538-4357/aad235 Bibcode: 2018ApJ...863..113H

Haywood, M.; Gómez, A.; Lehnert, M. D. +3 more

We investigate the nature of the double color-magnitude sequence observed in the Gaia DR2 HR diagram of stars with high transverse velocities. The stars in the reddest-color sequence are likely dominated by the dynamically hot tail of the thick disk population. Information from Nissen & Schuster and from the APOGEE survey suggests that stars i…

2018 The Astrophysical Journal
Gaia 300
The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z ∼ 3
DOI: 10.3847/1538-4357/aaed28 Bibcode: 2018ApJ...869..123S

Pettini, Max; Shapley, Alice E.; Steidel, Charles C. +5 more

We present results of a deep spectroscopic survey quantifying the statistics of the escape of ionizing radiation from star-forming galaxies at z ∼ 3. We measure the ratio of ionizing to non-ionizing UV flux density < {f}900{/f}1500{> }obs}, where f 900 is the mean flux density evaluated over the ra…

2018 The Astrophysical Journal
eHST 297
The White Dwarf Initial-Final Mass Relation for Progenitor Stars from 0.85 to 7.5 M
DOI: 10.3847/1538-4357/aadfd6 Bibcode: 2018ApJ...866...21C

Choi, Jieun; Ramirez-Ruiz, Enrico; Tremblay, P. -E. +2 more

We present the initial-final mass relation (IFMR) based on the self-consistent analysis of Sirius B and 79 white dwarfs from 13 star clusters. We have also acquired additional signal on eight white dwarfs previously analyzed in the NGC 2099 cluster field, four of which are consistent with membership. These re-observed white dwarfs have masses rang…

2018 The Astrophysical Journal
Gaia 291